Dr. Patrick T

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15 years, 177 days

MaplePrimes Activity

These are answers submitted by PatrickT

It sounds like a memory problem, though I haven't experienced it myself, here are some suggestions:

Tools --> Opions --> General --> Enable RTF copy set to Always

Try to use a "RAM cleaner" (for instance, this one to see if it solves the problem, if it does then the problem is not with Maple (and it's less inconvenient to use a RAM cleaner than restarting the PC), if it doesn't then the problem may be a memory allocation problem within Maple.

an example from yesterday:

maybe there's no analytical solution or, if there is, you'll have to help Maple find it. You can still go for a numerical solution, following the syntax shown above:

sys := diff(y[1](t),t,t) = -y[1](t)/sqrt(y[1](t)^2+y[2](t)^2)^3, diff(y[2](t),t,t) = -y[2](t)/sqrt(y[1](t)^2+y[2](t)^2)^3;
ini := y[1](0) = 1, y[2](0) = 0, (D(y[1]))(0) = 0, (D(y[2]))(0) = 1;
dsol := dsolve({sys,ini},{y[1](t),y[2](t)},numeric,range=0..1);

you can output the solution into an Array if you wish. Check dsolve,numeric for help. You can visualize the plot of the solution, for instance to plot y[1](t):


The help will show you how to visualize y[2](t) or make transformations of the ys...

See if this helps explain your problem:

The following should help you put the correct syntax together:

I don't know about msword, can it take pdf files? if so, you can convert from postscript to pdf without much loss in quality. Otherwise have you tried a screen capture? I find that often is not too bad. I use irfanview, freeware, I do a screen capture then paste into irfanview, then crop, it's alright for some graphs, not so good for others. The pdf solution I find to be usually very good.

I wanted to show how to add gridlines, but discovered I didn't know how to get a pretty output. Compare my two attempts.

Here, using Maple's options, I wasn't able to select the values of spacing() to get the plot to look good. Like Markiyan's plot above, I find the y-axis too cluttered. Perhaps Markiyan you know how to control that? [is there any difference between using logplot and plot with option mode=log ?]

plot( exp(-x)
  , x = .1 .. 10
  , 'axis[2]' = [ 'mode' = log, 'gridlines' = [ 5, 'color' = blue, 'subticks' = true ] ]
  , 'tickmarks' = [ default, spacing(10^(-3),10^(-1)) ]
  , 'labels' = [ "x", "y (log scale)" ]
) ;

Here, forcing some choices on Maple:

plot( exp(-x)
  , x = .1 .. 10
  , 'axis[2]' = [ 'mode' = log, 'gridlines' = [ 5, 'color' = blue, 'subticks' = true ] ]
  , 'tickmarks' = [ default, [1 = 1, seq(10^(-i) = 10^(convert(-i,symbol)), i = 1 .. 5, 1 ), 0 = 0] ]
  , 'view' = [default, 0 .. 1.3]
  , 'labels' = [ "x", "y (log scale)" ]
) ;

Hankel := p^2*diff(a(p),p,p)+p*diff(a(p),p)-R*a(p)+p^2*a(p)=0;
              /  2      \                                      
            2 | d       |     / d      \             2         
 Hankel := p  |---- a(p)| + p |--- a(p)| - R a(p) + p  a(p) = 0
              |   2     |     \ dp     /                       
              \ dp      /                                      
            [[_2nd_order, _with_linear_symmetries]]
Methods for second order ODEs:
--- Trying classification methods ---
trying a quadrature
checking if the LODE has constant coefficients
checking if the LODE is of Euler type
trying a symmetry of the form [xi=0, eta=F(x)]
checking if the LODE is missing 'y'
-> Trying a Liouvillian solution using Kovacic's algorithm
<- No Liouvillian solutions exists
-> Trying a solution in terms of special functions:
   -> Bessel
   <- Bessel successful
<- special function solution successful
                       / (1/2)   \              / (1/2)   \
     a(p) = _C1 BesselJ\R     , p/ + _C2 BesselY\R     , p/


is equivalent to:


try this, if all fails upload it and someone else will give it a try:

Your problem is not clearly stated.

Here's to get you started:

lambda := 10000;
k := 2*Pi/lambda;
a := 3000;
W := 500;
theta := Pi/6;

eq1 := x - a*sin(k*z) - W/2;
eq2 := x - a*sin(k*z) + W/2;
eq3 := x - z*tan(theta) + d*cos(theta);

Error, (in fsolve) d is in the equation, and is not solved for

fsolve(eval({eq1,eq3},d=2), {x,z});


maybe your styles have been defined to print inline in italics...

Format --> Styles, scroll down to Maple input --> Modify, select your font style and colour, it doesn't have to be red, you can have large font, etc.. (this really should be in Tools --> Options).

my current plan is to export images individually and recreate the display outside of Maple, within LateX to be precise. For this purpose I have written a procedure which takes a 3D plot and prints several displays based on different orientations. The procedure takes a 3D plot as input and prints a set of postscript files named on the basis of the plot name, e.g.,, etc.. The number of frames and the total angle of rotation (e.g. 360 degrees) may be specified. The option inline allows one to visualize inline an Array of the plots (before printing to file, works only for about 5 frames).

Any suggestions, remarks for improvement, very welcome, as usual.

MakeFrames := proc(p :: evaln
  , { frames :: posint := 5 }
  , { rotation :: posint := 360 }
  , { inline :: boolean := false }
  description "Takes a 3D plot structure and creates several frames at different angles of orientation. Options include: the number of frames; the complete angle of rotation (up to 360 degrees), inline displays the plots in an array, suitable for a small number of plots.";
  local i,j,n,r,A;
  A:=Array([ seq( plots:-display(eval(p), 'orientation' = [r*j/n,80]), j = 1 .. n ) ]);
  if inline then
    for i from 1 to n do # couldn't find a way to name with seq
    plotsetup('ps', 'plotoutput'=cat(convert(p,string),convert(i,string),".ps"),
    print( plots:-display( A[i], 'axesfont' = [ TIMES, 10 ], 'labelfont' = [ TIMES, ROMAN, 10] ) );
    end do;
  end if;
end proc:

Example of usage, based on the example plots given above:

MakeFrames(odeplot, 'inline' = true, 'rotation' = 180, 'frames' = 6);

My plan is to export these with the cmaple plot driver and to clean the postscript files directly (with tools developed here: ).

An alternative route was to convert the animated gifs produced by Maple into an avi (because gifs cannot be inserted into LaTeX documents while avis can), but I haven't found a way to do it (the top 3 search-engine-ranked links to convert gifs to avi didn't work with the Maple gifs), so instead I plan to use the LaTeX "animate" package, which uses pdf images to create an animation. And I plan to create the pdfs with the above procedure and the cleaning up process the url links to.

An interesting way to start 2012. Happy New Year to you!

Maple's help page, a selection


view=[xmin..xmax, ymin..ymax]


This option indicates the minimum and maximum coordinates of the curve to be displayed on the screen. The default is the entire curve.


coordinateview=[r1..r2, a1..a2]


This option is used only when the axiscoordinates option has the value polar. When that is the case, then r1..r2 specifies the radial range that is to be displayed and a1..a2 specifies the angular range.

Of possible relevance:

I seem to recall a discussion of these issues, with suggestions on how the plot renderer could be made smarter and detect a relevant range, but I couldn't locate it on mapleprimes, Alejandro may remember...

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